In gunnery practice, and especially air-to-air or ground-to-air gunnery where a target is towed by an airplane, it is advantageous to the teaching process and to the testing of performance capabilities of new aircraft to provide reliable scoring. Further, it is advantageous to provide the scoring as quickly and efficiently as possible. Further, the scoring system must be relatively inexpensive and easy to operate.
Most prior art systems use an active radar scorer mounted on the target. However, these prior art systems generally are unreliable because the target is not the center of the scored volume and, consequently, a built-in scoring bias is developed, or the extreme radio frequency noise environment created by the target causes the system to be unreliable. The target has an extreme noise environment because of vibrating or intermittant metal bonds, the radar cross-section of the target vehicle's metal surfaces is immensely larger than that of a bullet producing noise which is several orders of magnitude larger than the echo signal from the bullet, and debris falling off the target when it is struck by a bullet. Many prior art systems use antenna pattern control to prevent the transmitter and/or receiver from viewing the target vehicle, thus reducing the induced noise. This approach is limited in its effectiveness by the sidelobe amplitude of the antenna patterns and cannot provide the nearly omidirectional coverage required in many instances.